"...when aliens called the 'Dominators' attack 'Central City', 'Barry' (Grant Gustin) speeds over to 'Star City' to ask the 'Green Arrow' (Stephen Amell) for help in stopping them.

"Realizing the battle against the Dominators is bigger than they thought, they track down the 'Legends of Tomorrow', while Barry and 'Cisco' (Carlos Valdes) create a breach to bring back a secret weapon – 'Supergirl' (Melissa Benoist).

"Once all of the super friends are assembled, they come up with a plan to attack but a shocking secret related to 'Flashpoint'...

"...is revealed and suddenly no one is sure who they can trust.

"Then 'Wally' (Keiynan Lonsdale) wants to join the battle against the aliens but 'Iris' (Candice Patton) tells him he’s not ready..."